Some of my blueprints are fairly large...so large that it is so far zoomed out that I cannot the details clearly enough to remove unneeded stuff (such as a multiple stop train station w/ parking, and you get too much of the extraneous crap that you didn't want)

They could use "tutorial sandbox" to edit blueprints. In tutorial, player enters separate world with all necessary items and buildings, where You can play around. I wish, I can click a button on a blueprint, and "teleport" to such sandbox, where I can walk around blueprinted items, edit it, test it, save it, and exit...

Both ideas are excellent. I do like the idea of a blueprint sandbox especially, so that you can add items to a blueprint without having to place the old blueprint, add your missing item, delete the old blueprint, save the new blueprint and reformat the name and signals of the new blueprint. A lot of unnecessary steps there.

Part of me thinks this could affect speedrun times, but this can already be done in a roundabout way by going in another map to build the blueprint.

While your on the subject a request for very large blueprints.
As it stands if you have a blueprint that's more than roughly 250+ tiles long that you are trying to place, the edge of the blueprint will be off the edge of the screen no matter where you put the mouse so it's very hard to line up with things.
Would it be possible to have the blueprint placement ghost be relative to it's size and mouse location? As in, if the mouse is in the center of the screen the center of the blueprint ghost will be there. If the Mouse is at the edge of the screen the edge of the blueprint ghost will there there regardless of the size of the blueprint. Currently I'm just chopping blueprints up and placing them in a book, but you can't place a book inside a book so things are getting cluttered.

I wanted to highlight this issue (again!) And ask that this feature is added. The blueprint below is hardly large - a little over 11 or-so train car lengths yet editing it is a pain in the ass and frankly requires a magnifying glass.

58lnmn8ltr7nl7r8.png (326.9 KiB) Viewed 1148 times

This is a regular feature request, please add this big QoL improvement.